Well Water in Big Stone County: What to Test and Why

High Risk
Testing Strongly Recommended 5975 samples analyzed
Top Concerns in This County
Iron Arsenic Lead

Why This Happens Here

Groundwater in Big Stone County contains manganese, sulfate, arsenic, and several other contaminants that well owners should monitor. Multiple contaminants exceed EPA health standards, including arsenic, uranium, lead, and manganese, making water testing important for this area.

These contaminants come from the rock layers beneath the county. The underlying rock naturally contains these minerals and elements, which dissolve into groundwater as water moves through the ground over time. The local geology releases these substances into the water supply across the region.

Groundwater in this county is very hard and very high in sulfate, driven by dissolved minerals from the rock below. Iron also concentrates in the water as it passes through iron-bearing stone layers. These mineral-rich characteristics are common across wells throughout Big Stone County.

What This Means for You

Wells in Big Stone County commonly have arsenic, chloride, fluoride, iron, lead, manganese, sulfate, and uranium at levels above EPA health standards. Arsenic and uranium can increase cancer risk with long-term exposure. Lead harms children's brain development and learning. Manganese affects the nervous system. Fluoride at high levels can damage bones and teeth.

The very hard water and high sulfate levels in county wells create staining on fixtures and clothes, crusty buildup on pipes and appliances, and a bitter or salty taste. The water may smell like rotten eggs. Hard water also shortens the lifespan of water heaters and dishwashers by years. These problems compound when multiple minerals are present together.

We recommend a comprehensive water test for your well since multiple health concerns are present in the county. Every well is different, and your water could have higher or lower levels than what is common here. Testing is the only way to know what is actually in your water and what treatment will work best for your family. A comprehensive metals and minerals panel costs between $200 and $400. Treatment options like reverse osmosis, ion exchange, or aeration can remove or reduce many of these contaminants.

Not sure if your well is affected? Get certified results in 5–7 days.

Test Your Well Water with Tap Score →

Contaminant Detection Data

Contaminant Samples % Above MCL Distribution Confidence Risk
Manganese 3 100%
Low High
Sulfate 43 54%
Moderate High
Iron 7 50%
Low High
Arsenic 10 50%
Low High
Uranium 4 25%
Low High
Lead 12 17%
Low High
Chloride 51 6%
Moderate Moderate
Fluoride 20 5%
Moderate Moderate
HFPO-DA (GenX) ⓘ municipal 2 0%
Low Safe
PFOS ⓘ municipal 2 0%
Low Safe
PFNA ⓘ municipal 2 0%
Low Safe
PFHxS ⓘ municipal 2 0%
Low Safe
Nitrite 17 0%
Moderate Low
PFOA ⓘ municipal 2 0%
Low Safe
Fecal Coliform 1 0%
Low Safe
Total Coliform 1 0%
Low Safe
Hardness 22 Moderate Low
Nitrate 1 0%
Low Safe
Sodium 45 Moderate Low
pH 11 Low Low
PFBS ⓘ municipal 2
Low Safe

MCL = Maximum Contaminant Level (EPA limit for public water; used as benchmark for private wells). Distribution shows % of sampled wells in each concentration band. Methodology.

Data shows potential risk — a certified test confirms whether your water is affected.

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Population Health Context

Population-level CDC data. Not individual risk prediction.

9.5%
Cancer Prevalence
(state avg: 7.0%)
3.9%
Kidney Disease Rate
(state avg: 2.9%)
9.6%
Heart Disease Rate
(state avg: 6.6%)

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